Table 4.
Oxidative stress, electrocardiogram abnormalities, and blood pressure among workers in the lead–acid battery production industry according to doses of lead exposure.
| Low-dose exposure(n = 96) | Middle-dose exposure(n = 132) | High-dose exposure(n = 10) | P value | |
|---|---|---|---|---|
| T-SOD, U/mL | 42.8 ± 17.3 | 17.0 ± 14.7 | 8.2 ± 0.8 | <0.001 |
| MDA, µmol/L | 4.4 ± 1.0 | 6.4 ± 1.1 | 7.1 ± 0.8 | <0.001 |
| Systolic pressure, mmHg | 116.5 ± 10.2 | 121.4 ± 9.4 | 124.1 ± 16.7 | <0.001 |
| Diastolic pressure, mmHg | 76.6 ± 7.7 | 79.4 ± 7.4 | 82.5 ± 10.7 | 0.008 |
| Abnormal electrocardiogram | 13 (13.5) | 39 (29.5) | 5 (50.0) | 0.003 |
Data are expressed as mean ± standard deviation or n (%). T-SOD, serum total superoxide dismutase; MDA, malondialdehyde.
Different doses of lead exposure were defined according to the blood lead level: low-dose exposure, <100 µg/L; middle-dose exposure, 100–400 µg/L; and high-dose exposure, >400 µg/L.